Biology subjects

Socha, A.

Publications and source records attributed to Socha, A..

2 recordsLinked to original sources

bioRxiv2021

Natural variation in Arabidopsis ISR1 affects iron localization and induced systemic resistance

Beneficial root-associated bacteria can induce systemic resistance (ISR) to foliar pathogens and there is known transcriptional and genetic overlap in the root response to iron deficiency and ISR. A previous study found that there is natural variation in ISR among Arabidopsis accessions. The Ws accession is deficient in ISR, and the responsible recessive genetic locus, named ISR1, was mapped to chromosome 3. To find candidate genes that may underlie ISR deficiency in Ws, we identified genes that are induced in response to the ISR-triggering bacterium Pseudomonas simiae WCS417 and to iron stress and that have non-synonymous mutations in the Ws genome with respect to the ISR-responsive Col-0. We identified a kelch-domain containing protein encoded by At3g07720 that has a genomic rearrangement in Ws. We found that overexpression of Col-0 At3g07720 restores ISR to Ws, indicating that At3g07720 encodes ISR1. Isr1 loss of function mutants do not affect plant growth under iron limiting conditions but have increased levels of apoplastic iron. We found that iron supplementation, P. simiae WCS417, or a loss of isr1 enhance ROS production in a non-additive manner, suggesting they work through the same mechanism to enhance resistance. Our findings show that ISR1 is required for iron localization, immunity, and ISR, and suggest that increased iron uptake induced by ISR-eliciting bacteria may directly contribute to immunity through increased reactive oxygen production.

plant biology↗

bioRxiv2020

High-density Neural Recordings from Feline Sacral Dorsal Root Ganglia with Thin-film Array

Objective: Dorsal root ganglia (DRG) are promising sites for recording sensory activity. Current technologies for DRG recording are stiff and typically do not have sufficient site density for high-fidelity neural data techniques. Approach: In acute experiments, we demonstrate single-unit neural recordings in sacral DRG of anesthetized felines using a 4.5 m-thick, high-density flexible polyimide microelectrode array with 60 sites and 30-40 m site spacing. We delivered arrays into DRG with ultrananocrystalline diamond shuttles designed for high stiffness affording a smaller footprint. We recorded neural activity during sensory activation, including cutaneous brushing and bladder filling, as well as during electrical stimulation of the pudendal nerve and anal sphincter. We used specialized neural signal analysis software to sort densely packed neural signals. Main results: We successfully delivered arrays in five of six experiments and recorded single-unit sensory activity in four experiments. The median neural signal amplitude was 55 V peak-to-peak and the maximum unique units recorded at one array position was 260, with 157 driven by sensory or electrical stimulation. In one experiment, we used the neural analysis software to track eight sorted single units as the array was retracted ~500 m. Significance: This study is the first demonstration of ultrathin, flexible, high-density electronics delivered into DRG, with capabilities for recording and tracking sensory information that are a significant improvement over conventional DRG interfaces.

bioengineering↗